diff --git a/test.go b/test.go
index 9952d03..bd731b0 100644
--- a/test.go
+++ b/test.go
@@ -36,6 +36,7 @@ func ProbeFile(filename string) (err error) {
 		return
 	}
 
+	dumper := &atom.Dumper{}
 	var moov *atom.Movie
 
 	lr := &io.LimitedReader{R: osfile, N: finfo.Size()}
@@ -53,6 +54,9 @@ func ProbeFile(filename string) (err error) {
 				log.Println("read '%s' atom failed", cc4)
 				return
 			}
+			atom.WalkMovie(dumper, moov)
+		} else {
+			fmt.Println("atom:", cc4)
 		}
 
 		if _, err = atom.ReadDummy(lr, int(ar.N)); err != nil {
@@ -66,9 +70,6 @@ func ProbeFile(filename string) (err error) {
 		return
 	}
 
-	dumper := &atom.Dumper{}
-	atom.WalkMovie(dumper, moov)
-
 	return
 }
 
diff --git a/writer.go b/writer.go
index e58e701..76f6a46 100644
--- a/writer.go
+++ b/writer.go
@@ -13,6 +13,9 @@ type SimpleH264Writer struct {
 	SPS []byte
 	PPS []byte
 
+	Width int
+	Height int
+
 	duration int
 
 	sample *atom.SampleTable
@@ -33,6 +36,14 @@ func (self *SimpleH264Writer) prepare() (err error) {
 	self.sample = &atom.SampleTable{
 		SampleDesc: &atom.SampleDesc{
 			Avc1Desc: &atom.Avc1Desc{
+				DataRefIdx: 1,
+				HorizontalResolution: 72,
+				VorizontalResolution: 72,
+				Width: self.Width,
+				Height: self.Height,
+				FrameCount: 1,
+				Depth: 24,
+				ColorTableId: -1,
 				Conf: &atom.Avc1Conf{},
 			},
 		},
@@ -149,15 +160,18 @@ func (self *SimpleH264Writer) Finish() (err error) {
 		PreferredRate: atom.IntToFixed(1),
 		PreferredVolume: atom.IntToFixed(1),
 		Matrix: [9]int{0x10000, 0, 0, 0, 0x10000, 0, 0, 0, 0x40000000},
+		NextTrackId: 2,
 	}
 
 	track := &atom.Track{
 		Header: &atom.TrackHeader{
-			Flags: 0x0001, // enabled
+			TrackId: 1,
+			Flags: 0x0003, // Track enabled | Track in movie
 			Duration: self.duration,
 			Volume: atom.IntToFixed(1),
 			Matrix: [9]int{0x10000, 0, 0, 0, 0x10000, 0, 0, 0, 0x40000000},
-			TrackId: 1,
+			TrackWidth: atom.IntToFixed(self.Width),
+			TrackHeight: atom.IntToFixed(self.Height),
 		},
 
 		Media: &atom.Media{